Spill port control for free-piston units



May 10, 1949. K. c. COOPER SPILL PORT CONTROL FOR FREE-PISTON UNITSFiled Aug. 23, 1944 2 Shets-Sheet 1 wv NV vv ON INVENTOR- on 0N y 1949.K. c. COOPER 2,469,714

SPILL PORT CONTROL FOR FREE-PISTON UNITS Fi led Aug. 25, 1944 2Sheets-Sheet 2 'IIJ'IIA'I A i\\ 3 &

INVENTOR Fla. 2 M

Patented May 10, 1949 UNITED STATES PATENT OFFICE SP LL P RT EBEE QBEIQNKenneth G. @ooper, lortland, Goran assignor at!) United Aircraftflorporation, 'East Hartford, .flnnrn, a cnrpnrafinn of Delaware pplicaion Aus 3, Se ia No.- 559,

8 *UIaims. 1

August 23 1 9 new Patent No. '2,4=4=1;272, in i wh ch he spaced en s ofthe h nd are held ta- .get er'by a pr ng to keep the be d t ht on thecylinder. A Iea h e o th s invent on is a sel sealing band. which doesnot require a spring to maintain th han i her seal e position AnotherIeature is a sealing band which surrounds thecylinder andis guided by anoverlying stationary ring which has ports in, line with the ports in thecompressor cylinder.

A f at re of t i ve tio s a ightwe ght st u urec n oll th sp ll por s wch will require little power for adjusting it; and which will occupy asmall space.

Other objects and advantages will be apparent from the specification andclaims, and from the cc m ny n d gs which llust ate n e hodiment of theinvention.

Fig. l is a sectional view through *the freepiston unit.

Fig.2 is a sectional view.on .line 2-2 of Fig.

Fig, 3 is a fragmentary View on line iii-m3 of Fi The unit shownincludes aneng-ine cylinder I having reciprocating pistons 12, and M towhich iconipressor pistons l6 and 1.8 in cylinders 2,0 and 22 areintegrally connected. Sleeves 2.4 and 38 attached to the compressorpistons complete the reci r t ng piston blies sleeves si :eombinatienwith stationary pistons 28 and .30 riorni air spring cylinders.

The piston assemblies are moved apart by the burning of .fuel injectedinto eengine cylinder 110 thro gh one. or m ozzle 32- .A ompresse in theair spr ng c inders en the p wer strok returns the pistonassemblies."Theassemblies are always maintained at "equal distances from the cent rof the engine cylinders by :a linkage. not shown.

Intake manifold 42, which extends around the compressor and enginecylinders conducts air to intake valves 44 in the *heads of thecompressor cylinders, through which air alternately enters oppositeendsof the cylinders. The compressed air "leaves the cylinders throughdischarge valves '46, also at opposite ends of the compressor cylindersand passes "into a central scavenge chamber-48 and end chambers 50 and52. These chambers may be interconnected by a scavenge manifold, notshown.

Gompressed air from the scavenge chambers 'en'tersengine ports 54 and-56which-areuncovereel 'bypiston 2 and *l 4 at the 'end'o f the-powerstroke, thereby permitting air to be blown through the engine cylinder.Gas and air in the engine cylinders is discharged through exhaust ports58 into exhaust manifold '69.

Each compressor cylinder has one or more axially spaced rows of spillports 62 to permit discharge of air without compression from thecylinder. Each row of ports maybe individually controlled by a band -54,Fig. '3, extending around the cylinder between projecting ribs 66extending from the cylinder, and having spaced openings .68, Fig. 2,fQI' alignment with the "spill ports. Band '64 is relatively thin and issupported by a in 9 xte ing a ound he cy i e u si e of'the band andhaving spaced openings llwhich are n line ith the s ll po t :R n 0 may"be held posi n twe n the adjac nt pr tin ribs 66 thy clamping wires 14-fitting in grooves 16 i the rojecting ri s E ch g is nou large then band4 so hat the band is fr to move "be we n the outer periphery o t ecompre ser cylinder and he surroundin r n Band 4 may have vpmie t hglugs 18 01.1919.- zpositi ends fittingin notch s B0 in. a ear blocktzlece'ted b tween opposite ends f th rl n fine T e r block permits theband to be mov d .circumie entially or ali ning the openings in the h ndwith the p rts .in the cylinder- .Ass ewn, thehleehhas. areck .84 engain witha pinion- '6 eh a ha' t L88 parallel to the axis of thecompressor c linder, Rotat on of pinion. .96 will i. nst hand 54. fllhestructure by which the pini n. is wired. not being partior thisinvention. will not e described in detail,

Ihelugs '18 iii; i eely in s a block 82 to permit the hand lit tomoveinto engagement with the cy inder wa wh n th pressure in e cylinder isle s than the .ext rna pr ssure. If the pressure in the cylinder ishigher than the surrounding pre ure. the hand may mo e against the surounding ring when the band is in ports closing position. In either casethe band seals the ports '65 against leakage without the necessity for atensioning spring to hold the band on the cylinder.

It is to be understood that the invention is not limited to the specificembodiment herein illustrated and described, but may be used in otherways without departure from its spirit as defined by the followingclaims.

I claim:

1. A free-piston engine-and-compressor unit including a compressorpiston and cylinder, said cylinder havin at least one circumferentialrow of spill ports therein, a band extending circumferentially aroundsaid cylinder and being movable on said cylinder into a position tocover the ports, and a ring extending around the cylinder and overlyingthe band to form a channel in which the band may move, said ring havingports aligned with the ports in the cylinder, and said band having portsmovable into and out of alignment with the ports in the cylinder andring.

2. A free-piston engine-and-compressor unit including a compressorpiston and cylinder, said cylinder having at least one circumferentialrow of spill ports therein, a band extending circumferentially aroundsaid cylinder and being movable on said cylinder into a position tocover the ports, and a ring extending around the cylinder and, overlyingthe band, said ring having spaced ports aligned with the cylinder ports,said band having spaced openings therein corresponding to the spacing ofthe spill ports and being movable circumferentially between saidcylinder and ring for opening or closing the spill ports.

3. A free-piston engine-and-compressor unit including a compressorpiston and cylinder, said cylinder having at least one circumferentialrow of spill ports therein, a band extending circumferentially aroundsaid cylinder to cover the ports, said cylinder having guide meansthereon on opposite sides of the row of ports for guiding the band forcircumferential movement, and a ring extending around the cylinder andoverlying the band, said ring being connected to said guide means andhaving ports aligned with the ports in the cylinder, and said bandhaving spaced ports adapted for alignment with the cylinder 1 and ringports by movement of the band circumferentially between the ring andcylinder.

4. A free-piston engine-and-compressor unit including a compressorpiston and cylinder, said cylinder having at least one row of spillports therein, means on the cylinder for forming with said cylinder acircumferentiall extending guide channel overlying said row of ports,and a band movable circumferentially in said channel for opening andclosing said ports, said band having openings therein which are movedinto and out of alignment with the ports, said means having portsaligned with the cylinder ports.

5. A free-piston engine-and-compresso-r unit including a compressorpiston and cylinder, said cylinder having at least one circumferentialrow of spill ports therein, a band extending circumferentially aroundand movable on said cylinder to cover the ports and a ring extendingaround the cylinder and overlying the band, said ring having openingstherein aligning with the spill ports in the cylinder and said bandhaving openings movable into and out of alignment with the ports in thecylinder and with the openings in the ring by movement of the band onthe cylinder.

6. A free-piston engine-and-compressor unit including a compressorpiston and cylinder, said cylinder havin at least one circumferentialrow of spill ports therein, a band extending circumferentially aroundsaid cylinder and being movable on said cylinder into a position tocover the ports, and a ring extending around the cylinder and overlyingthe band to form a channel in which the band may move, said band havingspaced ports corresponding in spacing with the cylinder ports foralignment with the cylinder ports, said band being movable on thesurface of the cylinder for alignin the ports, said ring beingconstructed and arranged to provide for fiow of fluid into and out ofsaid cylinder when said ports in the band and cylinder are in alignment.

7. A free-piston engine-and-compressor unit including a compressorpiston and cylinder, said cylinder having at least one circumferentiallyextending row of spill ports therein, a band extending circumferentiallyaround the cylinder and being movable on the cylinder to close theports, said band having ports movable into and out of alignment with thecylinder ports, guide means on the cylinder on opposite sides of theports for guiding the band and a guide overlying the band and spacedfrom the cylinder to permit movement of the band between said guide andcylinder, said guide having ports aligned with the cylinder ports andbeing supported in position by said guide means.

8. A free-piston engine-and-compressor unit including a compressorpiston and cylinder, said cylinder having at least one circumferentiallyextending row of spill ports therein, a band extending around saidcylinder to cover the ports, guide means on the cylinder on oppositesides of the ports for guiding the band and a ring extending around thecylinder and overlying the band, said ring having ports aligned with thecylinder ports and being supported in overlying relation to the band bysaid guide means, said band having open ings therein which are movedinto and out of alignment with the .ports, said band having a projectinglug by means of which the band is moved, the ends of the ring beingspaced to accommodate the lugs.

KENNETH C. COOPER.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 877,492 Doelling Jan. 28, 19081,481,358 Dwyer Jan. 22, 1924 1,579,782 Riesner Apr. 6, 1926 2,016,613Pescara Oct. 8, 1935 2,038,442 Pescara Apr. 21, 1936 2,064,976 JanickeDec. 22, 1936 2,090,709 Steiner Aug. 24, 1937 2,108,890 Janicke Feb. 22,1938 2,139,425 Steiner Dec, 6, 1938 2,147,935 Steiner Feb. 21, 19392,426,311 Ledwith Aug. 26, 1947 2,441,272 Kalitinsky May 11, 19482,441,273 Kalitinsky May 11, 1948 FOREIGN PATENTS Number Country Date237,170 Germany 1910

